Thermographic recording system



PHENOLIC June 24, 1969 H. H. BAUM 3,451,338

THERMOGRAPHIC RECORDING SYSTEM Filed May 11, 1964 Sheet of 2 PHENOLIC MATERIAL ('I CHROMOGENIC MATERIAL (XI FIG. lb

'PHENOLIC MATERIAL CHROMOGENIC MATERIAL (x) .XXX. X XXXX XXX X PHENOLIC MATERIAL (IZHROMOGENIC MATERIAL (xI f F lG ld INFRA FIED RADIATION FIG. 20

sTAPLE SHEET I1:

FASTENER MATERIAL (I I l SEVERANCE LINE INFRA RED RADIATION IIIIIIII APER INVENTOR 7" EI N EERANCE HEN BAUM BY PHENOL'C CHROMOGENIC MATERIAL (X) MATERIAL A W I f HIS ATTORNEYS I June 24, 1969 HHBMJM I 3,451,338

THERMOGRAPHIC RECORDING SYSTEM Filed May 11. 1964 Sheet 3 of 2 INFRA RED RADIATION FIG. 3

SHEET III CHROMOGENIC MATERIAL (X) FIG. 4

PRESSURE PLATE |50c M TRANSFERABLE MIRROR IMAGE ON REAR SURFACE (EITHER ONE OF THE REAC- TANTS OR BOTH) INVENTOR HENRY H. BAUM 1" 44 ms ATTORNEYS PLAIN PAPER OR (SUPPLIED WITH ONE OF THE REACTANTS) United States Patent 3,451,338 THERMOGRAPHIC RECORDING SYSTEM Henry H. Baum, Dayton, Ohio, assignor to The National Cash Register Company, Dayton, Ohio, a corporation of Maryland Filed May 11, 1964, Ser. No. 366,524 Int. Cl. B41m 5/18 US. Cl. 101-469 12 Claims ABSTRACT OF THE DISCLOSURE There is provided by this invention a thermographic method of data-recording and heat-sensitive record sheets comprising chromogenic benzo-indolinospiropyran material and a di-phenol material capable of producing immediate and lasting color when and where the two co-reactant materials are brought into liquid contact, as in a melt. The two described co-reactant materials may be coated in a polymeric film binder on a single base web in interspersion in a single coat or separately incorporated into successive coats, or alternatively the coreactants may be coated on separate base web sheets to provide a co-reactive pair of sheets.

This invention relates to temperature-responsive record material, and particularly pertains to sheet material having particles of solid material becoming mobile as a fluid phase in recording processes involving thermographic temperatures with heat applied as radiant energy or conducted energy, the fluid mobile material making contact then or later with proximately-located co-reactant solid particles which also may become mobile as a fluid phase to produce a colored mark, and such mark itself being transferable to an unsensitized sheet either at the time the mark is made, or later.

The solid particles provided have a low vapor pressure at temperatures under 60 degrees centigrade (the maximum of living environment), to prevent loss of material by evaporation at room temperature, and will not react on solid-solid contact unless prolonged contact engenders such, so that, if the co-reactant substances are held separated by being on different sheets, the sheets may be brought into contact just before use in a recording operation to make a record by heat application thereto by radiation which produces a thermographic effect, or by conduction in some cases. If the co-reactants are situated in close proximity on the same sheet for providing storage before use and for providing a selfcontained sheet sensitive for making a record copy by itself, or two facing sheets are in prolonged contact before use, the particles are isolated against particle contact by their films of material, which will transmit the mobile reactants at the higher-than-60-degree-centigrade recording temperatures, which may range up to 200 degrees centigrade. Thus, where particles of both reactants are interspersed on a sheet, a thin binder of polymeric film material, just sufiicient to physically sheath the particles, is used, to prevent solid-solid contact or low vapor pressure contact and consequent premature coloration. If the particles of reactant are on different sheets, one or the other, or both, may have their solid particles of reactant isolated by a binder film material, or a common insert sheet or coating may be used, to separate the sheets. Where a minimum of binder is used between co-reacting particles on the same sheet, an over-layer of film may be used to prevent smudging by winding pressure or stack-contact pressures during storage or handling.

The fluid mobility produced in the reactants by thermographic temperatures is associated with the liquid or vapor state of the material at the high temperature.

The preferred color-producing reactants are phenols on one hand and certain photochromic benzo-indolinospiropyran compounds on the other hand. The preferred phenols are the di-phenols, and the preferred benzoindolinospiropyrans have the structure (with additional substitution in at least the 8' position).

where R, R, and R" are lower alkyl or phenyl groups. Most commonly R, R', and R" are methyl groups and in Table I may be so taken unless some other group is indicated by position number. Useful representative compounds are listed in Table I as follows:

TABLE I Melting point, degrees centigrade, of substituent derivative I 8-methoxy* 123-5 II 8-eth0xy 83-5 1-ethyl-8-1nethoxy 117-8 3-ethyl-8-methoxy 96-8 1-amyl-8-methoxy 72-7 1-pl1enyl8-methoxy# 161-4 3-phenyl-8 -n1ethoxy# -9 5-phenyl-8-methoxy# 167-71 5-phenyl-8-ethoxy# 119-22 7-phenyl-8-methoxy# 142-5 7-phenyl-8-ethoxy# 117-21 5chloro-8-methoxy -1 5-ehloro-8'-ethoxy 144-5 4,7-dichloro-8'-methox 90-100 5,8-dimethoxy -3 7,8-dimethoxy 4,7-dimethoxy-8-ethoxy 118-9 4,7-diethoxy-8methoxy 10-1-6 5,7 ,8 -trimethoxy 121-7 5,7-dimethoxy-8-ethoxy 111-3 4,7-dimethyl-8-methoxy 142-7 4,7-dimethyl-8-ethoxy 82-4 5-B-hydroxyethyl-8'-methoxy 78-85 6-chloro-8-methoxy* 123-125 6-bromo-8-methoxy 182-184 5,6dichloro-8-ethoxy, 125-126 1-ethyl-6 -ch1oro-8 -rnethoxy 9 l-ethyl-fi-bromo-8-methoxy 149-150 1-butyl-6-chloro-8-metho y 83-86 3-propyl-6-ehl0ro-8-methoxy 121-123 1-phenyl-8-eth0xy# 134-136 1-phenyl-3-ethyl-8-methoxy# 111-114 1-pl1enyl-3-propyl-8-methoxy# 145-147 1-phenyl-6-chloro-8-methoxy# 153-155 l-phenyl-S ,6-dichloro-8'-eth0xy# 121-122 B-propyl-3-phenyl-8-methoxy# 82 XXXIX- 3-amyl-7-phenyl-8-methoxy# XL 5,6-dichloro-8-methoxy 149-152 XLI. 5,8'-dimethoxy-chloro 155-157 XLIL. 7,8-dimethoxy-6-chloro. 104-106 XLIII. 4,7,8-tn'methoxy 104-106 XLIV. 4,7,8-trimethoxy-6-chloro 126-127 XLV, 6-nitro-8-methoxy 166-168 XLVI. 6'-methoxy-8-nitro 116-117 XLVIL 4,6,8-tri methoxy 132-133 XLVIII. 5-c oro-8-ethoxy 126-127 XLIX 4,7,6trichloro-8-methoxy. 121-127 5,8-dimethoxy-6-bromo 125 LL. 5'-bromo-8-methoxy- 183-185 LII 5'-ehloro-8-ruethoxy -161 Those compounds marked are most easily transferred in the colored st ate to another sheet, and those marked are difiicult to transfer in the colored state.

Norm-The absence of Roman numerals XVIII and XXVIII in Table I, an otherwise consecutive list, is of no significance.

The preferred compounds, as well as other indolinobenzospiropyran compounds, are made by previously disclosed methods; for example, the method disclosed in The Journal of the American Chemical Society, volume 81, 5605 (1959), which discloses that the general method for making this class of compounds consists essentially of condensing equi-molar amounts of a salicylaldehyde compound and a Z-methylene-l,3,3-trimethylindoline compound, both materials being so selected as to provide the desired substituent groups at desired positions on the 3 condensation reaction products; the methods disclosed in United States Patents Nos. 2,953,454 and 3,100,778; the conventional methods disclosed in Wizinger and Wenning, Helvetica. Chimica Acta, volume 23, 247 (1940); and methods which are obvious modifications over those cited above and which differ thereover primarily in the use of specific condensation reactants which yield desired indo- EXAMPLE I The 6' chloro-8'-meth0xy-1,3,3-trimethyl derivative A Solution of one mole of 3-methoxysalicylaldehyde (Tiemann, Koppe, Ber. 14, 2021 (1881) in 700 milliliters of glacial acetic acid is bubbled with chlorine, the temperature of the solution being held below 20 degrees centigrade, until a yellow precipitate separates. The precipitate is recrystallized from ethanol to give 0.40 mole of -chloro-3-methoxysalicylaldehyde with a melting point of 117 to 118 degrees centigrade.

To 0.4 mole of 1,3,3-trimethy1-2-methyleneindolino in 100 milliliters of ethanol is added 0.4 mole of 5-chloro-3- methoxysalicylaldehyde. The mixture is refluxed for two hours, filtered hot, cooled, and filtered again to give 0.35 mole of white powder with a melting point of 125 to 126 degrees centigrade.

This is the preferred chromogenic material for use in practicing the invention.

EXAMPLE 11 The 4,7,8-trimethoxy-I,3,3-trimethyl derivative- One mole of 2,5-dimethoxyaniline, one mole of acetoin, and four moles of zinc chloride are placed in a two-liter flask and heated to 160 degrees centigrade for one hour. The reaction mixture is cooled, washed several times with water, and extracted with ether. The ether is evaporated oil and distilled at 153 degrees centigrade/ 0.8 mm. of Hg to give 0.85 mole of 2,3-dimethyl-4,7-dimethoxyindole.

The indole (0.85 mole) thus obtained is methylated by being heated at 120 degrees for five hours in 100 milliliters of methanol with 2.55 moles of methyl iodide in a two-liter autoclave. The solid thus obtained is washed with 4 acetone, decomposed with base, extracted with ether, and distilled at 142 degrees centigrade/ 1.5-2.0 mm. of Hg to give 0.4 mole of 4,7-dimethoxy-1,3,3-trimethyl-2methyleneindoline.

To one mole of 4,7-dimethoxy-1,3,3-trimethyl-2-rnethyleneindoline in 200 milliliters of ethanol is added one mole of 3-methoxysalicylaldehyde (Tiemann, Koppe, Ber. 14, 2021 (1881) The mixture is refluxed for two hours, filtered while hot, cooled, and filtered a second time. The precipitate is recrystallized from ethanol to give 0.93 mole of White powder, melting point 105 to 106 degrees centigrade.

EXAMPLE III The 5-chl0r0-8'-methoxy-1,3,3-trimethyl derivative To one mole of 5-chloro-1,3,3trimethyl-2-methyleneindoline (Soc. Anon. Pour lInd. Chim. A Bale, Heinrich von Diesbach, Swiss 137,943, May 19, 1928) in 200 milliliters of ethanol is added one mole of 3-methoxysalicylaldehyde (Tiemann, Koppe, Ber. 14, 2021 (1881)). The mixture is refluxed for two hours, filtered hot, cooled and filtered a second time. The precipitate is recrystallized from ethanol to give 0.90 mole of white crystals, melting point 140 to 141 degrees centigrade.

EXAMPLE IV The 1-phenyl-8'-methoxy-3,3-dimethyl derivative To one mole of l-phenyl-3,3-dirnethyl-Z-methylene-indoline (Brunner, Ber. 31, 1943 (1898)) in 200 milliliters of ethanol is added one mole of 3-methoxysalicylaldehyde (Tiemann, Koppe, Ber. 14 2021 (1881)). The mixture is refluxed for two hours, filtered hot, cooled, and filtered a second time. The precipitate is recrystallized from ethanol to give 0.90 mole of white crystals, melting point 163 to 164 degrees centigrade.

The phenol compounds Structure Formula M.P., C.

A (CI 10500011 e-tertiary butylphenol 94-99 B OO-OH 4-phenvlph 166-167 C O0 OOH 4-hydroxydiphenyloxyde n a-Naphthol -96 E B-Naphthol L 119-122 F 0 H 0 0 O- O H MethyH-Hydroxybenzoate 126-128 G (EH30 0OOH 4-hydroxyacet0phenone 108-110 Structure Formula M.P., C.

(IJH; H;

V HO OH 4,4'-cyclohexylidene his (2-methyl- 184 phenol).

(31 0H 0H Cl W S- 2,2'-thio bis (4,6-dlehlorophenol) The Color combinations Following is a representative group of pairs of the color reactants and the color produced by their reaction.

Chromogenic material Phenol material Color Blue-black.

Do. Green-brown. Brown.

Do. Green-gray. Light gray. Green-gray. Blue-black. Dark blue. Green-blue. Green. Purple-black. Dark brown. Blue-black. Blue-gray. Light gray. Dark brown: Light gray.

Do. Light gray/yellow: Gray blue. Light gray. Brown. Dark blue. Light blue. Green-blue.

Light green/blue. Light gray. Green-blue. Purple-black. Blue-black. Blue-gray. Green. Purple-black. Dark blue. Green-black. Blue. Brown. Light brown; Orange. Brown.

aan :a weawwewoooozzzgagageeeer'wwm mmmmmomaweeeeeeoooom As to the organization of materials in functional arrangement The particles of sensitizing materials in unreacted colorless state or in reacted colored state may be organized with respect to support material and with respect to markreceiving material in a number of ways to make possible the production of multiple copies at once or serially, or to make recordings, on a single sheet or by use of a master sheet.

The preferred support sheet is paper because of its durability, absorbence, light and heat coefficients, opaqueness or translucense as desired, cheapness, and flexibility. However, film sheets of polymeric material, woven sheets, or bands of laminated materials may be used. The sheet used may be impregnated or coated with the sensitizing materials, such coating or impregnation fitting the proposed use as to depth of penetration of the reactants if penetration is involved, or with respect to the location of the reactants as to the broad surfaces of the sheet, or with respect to amounts and kinds of reactants. If the sheet is of solid film material, it should be penetrable by the fluid state of the reactants, or else the sensitizing materials should be situated at or on the surface of the sheet. The support material can be the surface of a thick plate, or of other more substantial structure than the sheet or plate form, providing that the support material does not act as a heat-sink to any large degree so that it interferes with the production of temperatures necessary to make marks or to transfer marks or marking reactants. The sheets should be as thin as is consistent with the proposed use, and for some purposes may be opaque and for other purposes may be of a translucent character, to enable data recorded on one side to be read from the other side. For the purposes of this disclosure, unless otherwise specified, it is to be considered that the support sheet is thin, relatively opaque white paper, and that any written or printed data to be used in conjunction therewith for control of recording be of a marking material that is raised in temperature relatively to the supporting member when both are commonly irradiated by infra-red radiation.

The particles of phenol material should be as small in size as is consistent for the necessary resolution and coating propertiessuch as, say, around three microns in average largest dimension-and the particles of chomogenie material should be of similar dimensions, although the size is not critical if the optical effect is sulficiently good with respect to resolution, as may result from the materials having been in mobile condition. In respect to resolution, the particles preferably should be supplied in such quantity in an area to be served as to give no perception of individual existence. All of the named materials either are colorless (white in powdered form) or have such small coloration in the unreacted form that they may be considered as leuco compounds.

Where no binder is to be used, it is important that the two reactants in unreacted state be on diiferent sheets, insulated by space or an intermediate insulator means until just before use, and separated thereafter if any unreacted materials remain in contact. Either reactant can exist alone on a sheet, or the reactants in reacted colored state can exist together with an unreacted residue, without physical insulation, and even one of the reactants can exist on a sheet in the presence of the reaction product mark without desensitizing the unreacted remaining area. Ordinarily, if two reactants are to be stored unreacted on the same sheet, they are disposed on the sheet with about a maximum of 25% or 30% of binder material to leave a thin film of such material around each of the particles that will not obstruct passage of the reactants in mobile condition in a recording operation. To further protect such a sheet from rough handling, or winding or stacking pressures, an overcoating of some film material is applied. It is within the scope of the invention to have the unreacted materials alone or in combination in a data-representing configuration or pattern on a sheet, such a pattern acting to control the transfer of material in the form of a pattern to an under sheet by a hot member applied generally to the sheet as distinguished from the application of heat in a pattern as determined by hot type or by thermography procedures.

Where both reactants are on the same sheet, they may be in interspersion or in layers, be one or both on the surface, partly beneath the surface, or entirely beneath the surface of a sheet. If in layers, the reactants with binder materials will not obscure vision of recorded data, as, at points where marks are produced, a fusion of the superimposed materials occurs.

It is within the scope of the invention, and is, indeed, an important part of the invention, to provide for the making of a master sheet copy from which a number of second-generation copies of a document may be made onto plain paper by heat and contact, without regard for or requiring the presence of the original document, or even as an incident of use of the original document if its back is sensitized according to one aspect of this invention.

The structural combination of elements in a number of forms illustrative of the invention is shown in the drawings which form part of this specification but which are not to be deemed to limit the claimed subject matter.

Of the drawings:

FIG. 1 is a schematic diagram of several constructions in cross-section of a sheet supplied with the reacting compound particles, (a) showing a sheet of film material or paper having the reactant particles located on a surface ,in interspersion, (b) showing the color reactant buried unit, and view (b) showing a folded sheet with a severance formation served with an interleaf sheet carrying one of the reactants. In FIG. 2, it is assumed that the chromogenic material is not rendered mobile by the temperatures used, but the phenol is transferred;

FIG. 3 shows both reactants on the rear surface of a sheet bearing thermographically-responsive data on the front surface, so that heat engendered by infra-red radiation striking the data heats it, which heat turns the materials on the rear surface to a pattern of colored mobile fluid which is transferred to a plain sheet of paper placed in contact therewith; and

FIG. 4 shows an overlying sheet of paper having a mirror-image of data recorded in terms of one or both of the reactants on the rear surface of a sheet, so that it may be passed to a plain sheet in a mobile fluid phase by a heat press; the plain sheet also may be supplied with one of the necessary reactants if it is missing, by intention, from the overlying sheet.

Preliminary to specifying how the record member sheets are made, it should be understood that, if the reactant material is to be applied to a base sheet as a solution, it should not come into contact in the liquid solution state with the other reactant, because color will be produced prematurely. In those instances where a sheet is to be entirely coated with the reaction product, for transfer purposes, the reactants may be applied as solutions and dried. However, for all the purposes of this invention, the preferred form of applying the reactant materials is by coating anon-solvent liquid dispersion thereof on the base sheet.

In the event that reactant surfaces of two sheets are to be placed or kept in contact, or a stack of sheets having the two reactants coated on one side is to be kept in storage, either as already-made records or as sheets to be recorded upon, a protective overcoating of film material of one to two pounds per ream of 25-inch by 38-inch sheets is applied to the active surfaces. As an effective example of such protective coating composition, the following is specified:

Protective overcoating.-Composition Parts by weight Polyvinyl alcohol 75 Sodium carboxymethylcellulose 25 Water 1,000

In the following discussion of the preparation and use of different kinds of coated sheets, sheets I, II and III are those illustrated in the drawings. In each case the sheets so designated may have a light coating weight (sheets IA, IIA, and IHA) for use as receiving or copy sheets or a heavier coating weight (sheets IB, IIB and IIIB) for use as transfer sheets. In the discussion, sheet I," sheet II, or sheet 111 is used to designate the sheets in cases where it is not necessary or appropriate to designate the coating weight. The A and B designations are added where the coating weight of the sheet is relevant to the discusslon.

Making a phenol-particle-coated sheet I A ball mill is loaded with the following composition:

Parts by weight Wet Solids 4,4-isopropylidene (ii-phenol 85 W er v Hydroxyethylcellulose 7.5% aqueous solution-.. 200 15 Making a sheet coated with chromogenic particles.Sheet II A ball mill is loaded with the following composition:

Parts by weight Wet Dry 1,3,3-trimethyl-6-eh1oro-8-methoxy-indolinobenzo-spiropyran 70 70 Polyvinyl alcohol (88% hydrolyzed) 7 5% solution in water 400 30 Water 80 and the contents milled to an average particle size of three microns. For use as a receiving sheet (sheet IIA), a oneto-two-pound, dried weight, coating per ream, as specified, is sufiicient, whereas for a transfer sheet of this construction (sheet IIB), three to four pounds dried weight per ream should be used.

Making a sheet coated with both phenol particles and chromogenic particles III A ball mill is loaded with the following composition:

and is run until the solid particle size averages three microns, to form a coating material which is applied to paper in an amount to yield a coating of two to three pounds per ream, dried weight, for use as a heat-responsive copy sheet (sheet IIIA). If a reflex copy system is used-that is, where the sheet must be penetrated by infra-red 1ighta thin paper base sheet is used. For use as a transfer sheet (sheet IIIB), three to five pounds, dried weight, of coating per ream is used.

A protective overcoating should be used with these sheets when they are in close storage.

Equivalent binder materials Equivalents for hydroxyethylcellulose as binder materials are:

those followed by an asterisk being found most useful.

The use of Sheets I and II together In this instance of use, sheets I and II (FIG. 2a) are placed in face-to-face relation, and either can be the copy sheet. The original data is pre-recorded on the uncoated side of the selected sheet to provide thermographic responsive representation of the data. On heating of the data with infra-red radiation, while the coated sides are in contact, the copy will appear on the coated surface of both sheets. The infra-red radiation, in the interests of efliciency, should be applied directly to the thermographically responsive data. It is thus to be noted that either sheet I or sheet II can be a'copy-receiving sheet; in this instance,

sheet II has a mirror-image of the data. If the copy made is to be transferred, then the heavier coatings should be used, typified by specified sheets IA and HA. Direct reading images and mirror-images, therefore, may be made according to the arrangement of sheets with respect to each other, and the applied energy, according to the well-known optical and transfer laws governing copying procedures.

The use of sheet III This sheet III may be used alone as a copy-receiving sheet by being served with a pattern of heat from front or back, as by thermographic original document, by trace of a hot stylus, by hot type, or by any other means giving a differential heat pattern.

If the heavier coating is used, the sheet may be used for a transfer sheet to produce multiple copies on plain surfaces of any sort, such as bond paper, newsprint, cloth, film, and the like, as long as the pattern of heat is present to control the transfer.

The use of an interleaved sheet If the document to be copied is not sensitized on the rear surface, the missing reactant may be supplied by means of an interleaved sheet, as shown in FIG. 2b.

The use of sheet III as a master sheet (direct) Sheet III, as the more heavily coated sheet (sheet IIIB), has the data to be recorded printed on the uncoated side. The coated side is placed against plain paper to form a record pair, which is passed by a light source of infrared wave length, so that the radiation directly strikes the printing. A copy of the recorded data will appear on the plain paper. This can be repeated until the coating is exhausted.

The use of sheet III (or sheets I and II) as a master sheet (intermediate) The heavier coated sheet I'IIB is written on with thermographic ink directly on the coated side. A piece of plain paper is placed in contact with the writing on sheet II IB to form a pair, and the pair is subjected to infrared radiation. This puts a colored mirror-image of the recorded data on the plain paper. This plain sheet then may be used over and over against successive sheets of plain paper, and each pair is subjected to a hot press to transfer the colored image in direct reading form.

If a sheet IA has recording on its coated side in terms of thermographic ink, and a pair is formed by contact of a plain sheet of paper placed thereagainst and subjected to infra-red radiation, the mirror-image of the recorded data will appear on the plain sheet in mirrorimage form. This mirror-image then is transferred to the coated surface of a sheet {[I and subjected to application of heat by use of a hot plate. The direct reading image will appear on sheet H, and this operation may be repeated with other type II sheets until the pattern of material is exhausted.

If a sheet I'IA has a recording on its coated surface in terms of thermographic ink and is pressed against a sheet I type coated surface and the pair is subjected to infrared radiation, it forms a mirror-image master sheet, which may be used to transfer the data to a type I sheet successively until the mirror-image is exhausted.

'It has been mentioned that the reactant materials in whole, or in part, may be placed within the boundaries of a sheet, and such placement may be made by mixing particles of the reactant in the head-box furnish of a paper-making machine, or coated on a wet sheet of paperstock furnish before the drying of it to a completed paper sheet. The amount and the depth of distribution of the buried particles all have a bearing on the effectiveness 13 of such sheets, and optimum conditions quantitatively can be determined for a particular base sheet, energy source, and other variable factors by empirical test, all well within the skill of one familiar with the art.

While many phenol compounds, particularly di-phenol compounds, have been disclosed, it is their acidic nature in the mobile fluid state of the material that makes them valuable for carrying out and practicing the invention; hence equivalents in acid activity and in ability to form a mobile fluid phase at thermographic temperatures, together with low vapor pressure at temperatures below 60 degree centigrade, are to be considered as forming a criterion for the selection of equivalents.

What is claimed is:

1. A record member including a support sheet having a record surface of solid particles of phenol material as a first reactant and solid particles of chromogenic benzoindolinospiropyran material as a second reactant which is colora'ble on reaction contact with the phenol material, said particles of phenol and chromogenic material reactants producing color by at least one of the reactants becoming mobile as a fluid phase at temperatures associated with thermographic phenomena, said solid phenol particles being insulated from solid contact with the proximate solid particles of chromogenic material by a thin polymeric material film that is pervious to the thermographically-produced mobile phases of the reactant materials.

2. The record material of claim 1 in which the phenol material is of the di-phenol class.

3. A record member including a support sheet having a record surface of minute particles of phenol material which are solid at the maximum living environment temperature (60 degrees centigrade) and having a mobile fluid phase in marking quantity at the higher temperatures encountered in thermographic phenomena, and proximately positioned in contiguity to, but spaced apart from, the particles of phenol by a polymeric material film, an equivalent, from a reaction standpoint, amount of solid particles of chromogenic material of the benzo-indolinospiropyran type also being solid at temperatures below 60 degrees centigrade and having a mobile fluid phase at temperatures associated with thermographic phenomena, said polymeric material affording isolation of the solid particles of chromogenic material from the solid particles of phenol but passing either kind of particles material in the mobile fluid state phase produced by thermographic temperatures.

4. A sheet of record material having on a surface thereof a visually continuous coating of the reaction prod not of a di-phenol compound and a benzo-indolinospiropyran compound, said reaction product being convertible to a mobile fluid phase by temperatures associated with thermography.

5. A sheet of record material having on a surface thereof a heat-transferable coating of the reaction product of a di-phenol compound and a benzo-indolinospiropyran compound arranged in data-representing configuration.

6. A sheet of record material having on a surface thereof a heat-transferable coating of the reaction product of a phenol compound and a benzo-indolinospiropyran compound.

7. The record material of claim 6 wherein the coating is arranged in the configuration of recorded data, whereby a general heating of the record material will produce a mobile fluid phase of the recorded data as a colored pattern for transfer to another sheet by contact.

8. The sheet of record material of claim 6 in which the benzo-indolinospiropyran compound is the compound 9. A sheet of record material having on a surface thereof a coating of the reaction product of a phenol compound and a benzo-indolinospiropyran compound arranged in data-representing configuration.

10. A method of making copies of recorded data on plain paper including the steps of forming on a surface of a proposed master sheet the mirrro-image of the data in terms of the reaction product of a phenol compound and a benzo-indolinospiropyran compound; placing the mirror-image surface against a plain paper sheet to form a contact pair; and applying heat to the pair sufficient to form a mobile fluid phase of the reaction product image and to transfer such a portion of said fluid phase to the plain paper as adheres thereto.

11. A pair of record material sheets operable in faceto-face contact, each sheet being supplied with material in solid form which turns to a mobile fluid phase at temperatures associated with thermographic phenomena and the material on one sheet reacting on contact with the material on the other sheet, if only one of the materials is in a fluid state, to produce a distinctive color, one of the component materials being a phenol compound and the other material being a chromogenic benzo-indolin0- spiropyran compound, both materials being in solid state below 60 degrees centigrade.

12. A master sheet for use in controlling and supplying material for the production of multiple copies of data on successively presented sheets of copy record material brought into contact therewith, said master sheet having on the contacting surface a transfer coating including a finely interspersed juxtaposed array of particles including a phenol compound and a benzo-indolinospiropyran compound which react at thermographic temperatures to produce a marking material capable of transfer to a copyreceiving sheet.

References Cited UNITED STATES PATENTS 2,967,785 1/1961 Allen et al ll736.8 XR 3,239,366 3/1966 Miller et al. 3,244,550 4/1966 Farnham et al. 101-473 XR 3,262,386 7/1966 Gordon 101469 3,280,735 10/1966 Clark et al. 101470 DAVID KLEIN, Primary Examiner.

US. Cl. X.R. 

